code: def setup_method(self):
      self.n = 10
      self.A = lowerBidiagonalMatrix(20, self.n)
      self.xtrue = transpose(arange(self.n, 0, -1))
      self.Afun = aslinearoperator(self.A)
      self.b = self.Afun.matvec(self.xtrue)
      self.x0 = ones(self.n)
      self.x00 = self.x0.copy()
      self.returnValues = lsmr(self.A, self.b)
      self.returnValuesX0 = lsmr(self.A, self.b, x0=self.x0)
  
imports: from numpy import array, arange, eye, zeros, ones, transpose, hstack
  from numpy.linalg import norm
  from numpy.testing import assert_allclose
  import pytest
  from scipy.sparse import coo_matrix
  from scipy.sparse.linalg._interface import aslinearoperator
  from scipy.sparse.linalg import lsmr
  from .test_lsqr import G, b
label_desc: Use image node_id 1 for calling the TestLSMRReturns obj's underlying member method code with example usage: obj.setup_method() without return types